Foam forming apparatus



Filed July 5. 1929 INVENTOR law's 6 Morris 7222 5022 ATTORN Patented May 9, 1 933 "UNITED STATES. PATENT OFFICE m 6-. 103318 T'IIPBOII', OI PLAINIIELD, NEW JERSEY, ASSIGITOR TO PYREN 11mm CORPORATION, A CORPORATION 01 DELAWARE FOLK IOBII'NG APPARATUS Application fled July 5,

. i added to a stream of water to form foam for fire fighting purposes.

Various forms of apparatus for introducin chemicals to a stream of water for fire fig ting purposes have been developed from 10 time to time. The devices proposed have operated on difierent princip es and with varying degrees of success. In the earlier devlces mechanical means were sometimes provlded for feeding the powder or liquid chemicals to u the stream of water and several dev1ces have been developed to rate on the prmclple of the ejector, means iliiglprovided for feeding the chemical to the e d of action of the ejector. A device of this'general character n is shown in the patent granted to Hans Burmeister No. 1,823,559 on September 15, 1931. hurmeister device w ich represents a recent development a foam forming powder In the is carried to t e ejector by a subsidiary water stream. The present invention constitutes an improvement on the device shown by Burmeister. In principle there is a floor or plate upon which the powder is supported and from which it is washed into a slurry well from which it is drawn by ejector. The nature and objects of the inventlon will be better understood from a description of a particular apparatus for the purposes of which description'reference should be had to the accompan ing drawing forming a part hereof and in w ich The figure is a central sectional view of a foam forming apparatus constructedin accordance with the invention.

The apparatus shown for the urposes of illustrating the principles of the invention is designed to be connected in ahose line for the purpose of adding foam forming powder to the stream of water of the hose line. As

shown it comprises a hopper into which foam forming powder can be introduced from time to time, the o eration of the up paratus being such that t e powder is added t a stre m of water received from the h e the suction of the 1929. Serial No. $170,019.

or pipe line 6. At one side of the bottom of the hopper 5 is provided a mixin well or slurry well 7 into which the powder is washed to form a slurry by water flowing into the hopper through a nozzle 8 connected tothe pipe line 6. In the well 7 an e'ector is shown as arranged vertically an acting up wardly to force out the slurry formed in the slurry well and to introduce this slurry into the stream of water to form foam. The quantlty of water passing through the ejector and the uantity of powder washed down by the nozz e will vary with the increase and decrease of pressure in the main thus maintaining the proportion relatively constant. The lower side wall 51 as shown may be considered as a plate against which the owder is supported and from which it is was ed by the stream of water flowing from the nozzle and over the plate. v

As shown in the drawing the nozzle8 is located slightly more than half way down from the to of the hopper. This location is so chosen tat brid 'ng. or arching of the chemicals within the opper in such a way as to prevent the feeding of the chemicals by avity into the path of the stream pro'ected y the nozzle is definitely avoided. t will be found that in a hopper having sloping sides, converging at an angle of about as indicated, the weight of the chemicals will an extent that an arch might be formed across the hopper to a point about one-third up from the bottom or even slightly higher. When such archin occurs the material beneath it may be wit drawn and the material above will not break the arch so that gravity feed produce packing toward the bottom to such would be interfered with. Such arching can-v not occur, however, above a point materially more than one-third of the way up from the bottom of such a hopper. By locating the discharge end of the nozzle 8 well over onethird, and perferably nearly half way up, it is insured that no arching will occur above the nozzles Any arch which may be temporarily formed below the nozzle will be broken by the action of the stream directed downwardly by the nozzle. Accordingly the free g a y ee of the ohezul als into the I path of the stream and the washing of the chemicals the stream into the slurry well is insured.- p

The hopper is shown as supported on the pipe connections between the pipe 6 on the one hand and nozzle 8 and ejector 10 on the otherhand. As shown pipe sections 11 and .12] with suitable connections form a frame supporting the hopper and are in turn supported by legs 13 secured to the pipe section 12. A cross bar 15 on the top of the hopper serves to stiffen the same and to provide a handle whereby the apparatus can be carried.

The slurry well is shown as of substantial size and as extending-upwardly above the in- I let opening 16 from the bottom of the hopper.

The well is closed. at the top to provide a closed foam-forming chamber in which the foamformed in the well may rise but from which it may not escape except through the ejector 10.

The pressure' within the slurry Well will normally vary during the operation ofthe device, sometimes being above normal atmospheric pressure. In order to .prevent the formation of a partial vacuum a check valve '18 is preferably provided which will admit air from the exterior of the casing into the slurry well but will prevent escape of foam.

or sludge therefrom.

The ejector outlet which is made in sections 19' and 20 preferably tapers outwardly as shown. 4

The foregoin particular description is illustrative mere y and is not intended as defining the limits of the invention.

In the operation of the device the hopper .5-will be continuously supplied with foam forming chemicals while water under suitable pressure will be forced through the nozzle 8 and the ejector. As-shown the relative areas of the nozzle 8 and the ejector nozzle go to the nozzle 8 and nine-ten e ector. The water discharged by the nozzle will preferably be about one to nine, their orifice diameters being about in the ratio of one to three. This means that approximately one-tenth of the; water supplied by pipe 6 will t s to the 8 willcontinually force a mixture of chemicals and water under pressure into the slurry well and into the'rough outer surface of the stream discharged by the ejector nozzle. The

slurry thus entrained Ior pocketed in the water stream will be carried b the impact or momentum of the stream and 'deliveredto the point of use. 4

M I claim: q 1. In a fire fighting apparatus the combination with a hopper for receiving dry pow.- der, of aslurry well at one side of the bottom a .water'supply pipe, a nozzle connected to Openin of the ho per, a check valve connected to said- %o well to a mit air thereto when-pressure withper to wash powder into the slurry well and form a slurrryand an ejector positioned vertically in the slurry well to lift the slurry upconnections from said con uit for supplying water to'said ejector.

guishing foam a hopper adapted to receive a charge of foam producing chemicals, the

walls ofsaid hopper converging toward an 3.- In apparatus for producing fire extinoutlet adjacent the bottom, the convergence of said-walls beingisuch that archin of said chemicals cannot occur materially a ove onethird the height of the hopper above the bottom, one of saidwalls forming an inclined retaining surface for the chemicals, means for directing a stream against said surface, 4

said means having its discharge end disposed within said hopper at a point more than onethird the way up from the bottom of the hopper, which is above that at which an ob-,

structingarch can be formed by said chemicals, a slurry well in communication with the outlet --of said hopper, an ejector associated with'said slurry well for removing the slurry therefrom, and means for conveying water I to said stream directing means and to said ejector.

4. In apparatus for producing fireextinguishing foam a hopper forreceiving foam forming chemicals, said hopper having a fun- I nel shaped bottom portion, the walls of said hopper converging at such an angle as to prevent archin of said'chemicals above a point materially elow, a plane half way between the top and bottom of the hopper, said-bottom portion "having an opening at one side and a wall vextendlngacross the bottom of the-hopper toward said opening, said wall being adapted to'supportsai d foam,forming chemicals within the hopper, .a nozzle within the hopper having its outlet substantially midway between the top and bottom of the hopper which is at a point where the restriction is insuflicient to permit an obstructing arch to be formed by said chemicals,

said nozzle being'direeted toward said-wall,

"a slurry wellin communication with said means for'supplying water tosaid nozzle wash the chemicals from saidwall into said slurry well, and means for discharging the slurry from said well.

5. In apparatus for producing fire extinas said supply pipe and positioned in'the h pguishing foam a hopper adap ed to receive foam forming chemicals, said hopper having converging walls forming a channel of decreasing cross sectional area toward the bottom, said channel being of sufficient dimension adjacent the top to prevent formation of said chemicalsinto an obstructing arch but being so arranged at the bottom as to permit such arching of the chemicals up to a point approximately one-third the distance from the bottom, means for directing a stream of water into said chemicals at a point between one-third and one-half the distance from the bottom of the hopper which is above that at which such arching may occur, and means for collecting and discharging the slurry formed by said water.

6. In apparatus for producing fire extin- 'e ector.

guishingfoam ahopper adapted to receive foam forming chemicals, the walls of said hopper converging at an angle of approxi mately. 45, a nozzle within the hopper having its outlet at a point substantially midway ducing chemicals which comprises directingname to this specification this 2nd day of July 1929.

LEWIS G. MORRIS TIMPSQN,

between the top and bottom, thereof and so directed as to discharge against a wall thereof, a slurry well in communication-with the bottom of the hopper, an ejector for removing the slurry from said well, and means for supplying water to said nozzle and said 7. In apparatus for producing fire extinguishing foam a hopper adapted to recei ve foam forming chemicals, the walls of said hopper converging at an angle of approximately 45, a nozzle within the hopper having its outlet at a point substantially midway between the top and bottom thereof, 'a slurry well in communication with the bottom of the hopper, an ejector for removing theslurry from said well, and means for supp ying water to said nozzle and said ejector, said means directing approximately of the water throughsaid nozzle. 8. The method f producing fire extinfinishing foam which consists incharging a, ry mixture of foam forming chemicals into a ho perhaving conver .sides which woul permit'arching only a of the way up from the bottom, positively washing said dry mixture out of the hopper by means of a downwardly directed jet of V water under r'essure in quantities suflicient to form a sli e or suspension, said jet'being directed into-the chemicals at a point well over one-third of the way up from the bottom of the hopper, the resultant sludge being fed by the action of the water to' an ejector or the likeplaced outside the hopper in a water stream which provides the main portion of the energy required to deliver the foamto the point of. use and which also serves to dilute the sludge to the extent required.

ut one-third 9. The method of producing-ffire extin-o guishing foam-- with a hopper having side walls v91 ging at an angle of about and W H mixture of ioampm- 

